Due to the requirements of high-speed data processing, manufacturing and design of central processing units (CPUs) are being improved constantly to further more powerful function and faster operating speed. Meanwhile, operating voltage and frequency are also increasing. As a result, the thermal generation power of CPUs is increasing significantly. Excessive high operation temperature affects the normal operation of the CPU. Hence good heat-dissipating devices are indispensable in computer systems. As the technology of the CPU improves, heat-dissipating devices also have to keep up with the CPU to meet its requirements.
The commonly used heat-dissipating devices at present include a heat sink and a fan. The heat sink has a body and a plurality of fins formed on the body. The body of the heat sink is contacted with the CPU for transmitting the heat generated from the CPU to the fins. The fins are designed to increase the heat dissipation area. The fan is mounted onto the heat sink to provide airflow to flow through the fins. The fins undergo heat exchange with the external air to dissipate heat.
At present time the assembly of the fan and the heat sink mostly adopts screws by which the periphery of the fan has corresponding apertures to receive screws so as to fasten the fan to the heat sink. There are two assembling methods. One approach is to omit the fins where the apertures are positioned (or the fins are spaced to form an accommodating area) to enable the screw to be directly fastened to the body of the heat sink. Such a construction requires a corresponding design for the fins (omitting the fins or forming a space between two fins) and thus increases production processes. In addition, to meet different heat-dissipating requirements, the heights of the fins are also different. Hence, different heat sinks require screw of different lengths. This creates many assembly problems. The other approach is to mount the fan onto the fins of the heat sink. The screw are directly fastened to the fins. However, the fins generally cannot withstand a great screwing force, and the fins are prone to deformation when the screw are fastened. As a result, supporting the fan is difficult or even impossible.